The present disclosure relates to a multilayer ceramic capacitor (MLCC) and a board having the same.
In accordance with the recent trend toward miniaturization and increases in capacitance of electronic products, demand has increased for electronic components having a small size and high capacitance to be used in such electronic products.
Among such components, in the case of multilayer ceramic capacitors, when equivalent series inductance (hereinafter, referred to as “ESL”) increases, performance of an electronic product may be deteriorated. In addition, as the electronic components have been miniaturized and had high capacitance implemented therein, an influence of an increase in ESL of the multilayer ceramic capacitor on reductions in performance of the electronic component relatively increases.
In this case, a quality coefficient associated with a relationship between inductance, capacitance, and resistance components of the capacitor is referred to as a quality (Q) factor.
Recently, in an electronic device such as a high performance smartphone, a multilayer ceramic capacitor having a high Q factor in a frequency region of several hundred MHz to several GHz should be used for communications. In this frequency region, a Q factor value is significantly affected by a resistance component of an electrode.
In order to increase the Q factor value, a method of stacking two layers of internal electrodes having the same polarity may be used.
However, it has been difficult to use this method to increase the Q factor value for all multilayer ceramic capacitors. For example, some multilayer ceramic capacitors have capacitance in a range in which it is difficult to use a double-layer internal electrode structure. Furthermore, only certain characteristics may be implemented by the double-layer internal electrode structure, among multilayer ceramic capacitors using C0G characteristics in which a capacitance change with respect to a temperature is low.
In addition, even in the case that the multilayer ceramic capacitor is formed by stacking two layers of internal electrodes having the same polarity as each other as described above, an effect of increasing the Q factor value is not large, as compared to an increase in the number of stacked layers due to a skin effect and a proximity effect, and there is a limitation in an amount of capacitance to be implemented, such that it may be difficult to apply this method to a small-sized multilayer ceramic capacitor.
Furthermore, after compression, at the time of manufacturing a product, there is a difference in degrees of density between a portion of the multilayer ceramic capacitor in which the internal electrode is printed and a portion thereof in which the internal electrode is not printed. Particularly, the difference is largest in an end portion of the internal electrode, which may increase the likelihood that cracks will occur due to a difference in shrinkage/expansion rates at the time of sintering the product. The thicker the internal electrode, or the larger the number of internal electrodes, the greater the difference in thickness, such that the probability that cracks will occur may be increased.
According to the method as described above, the internal electrodes having the same polarity as each other are adjacent to each other in a stacking direction, which may cause an increase in the occurrence rate of structural defects due to a difference in internal stress.